Add a new schema function to validate Valibot schemas

[andrewmd5]

Description

I have a use-case where I need to create an object that contains a schema as one of its members. Ideally, I would like to define it like this:

schema: v.pipe(v.schema(), v.transform((s) => toJsonSchema(s)))

However, the only current way to do this is:

schema: v.pipe(
  v.custom<v.BaseSchema<unknown, unknown, v.BaseIssue<unknown>>>(() => true),
  v.transform((s) => toJsonSchema(s))
)

Which does work, but not sure what kind of side effects it will have:

const AutoCompleteSchema = object({
  resolver: pipe(
    string(),
    trim(),
    nonEmpty(),
    regex(/^\/(?:[a-z0-9\-._~%!$&'()*+,;=:@]+(?:\/[a-z0-9\-._~%!$&'()*+,;=:@]+)*)\/?$/)
  ),
  method: picklist(['GET', 'POST']),
  schema: pipe(custom<BaseSchema<unknown, unknown, BaseIssue<unknown>>>(() => true), transform(toJsonSchema)),
});

const data: InferInput<typeof AutoCompleteSchema> = {
  resolver: "/yes/",
  method: "GET",
  schema: object({
    test: string(),
  })
}

const ff = safeParse(AutoCompleteSchema, data);
if (ff.success) {
  console.log(JSON.stringify(ff.output));
}

{
   "resolver":"/yes/",
   "method":"GET",
   "schema":{
      "$schema":"http://json-schema.org/draft-07/schema#",
      "type":"object",
      "properties":{
         "test":{
            "type":"string"
         }
      },
      "required":[
         "test"
      ]
   }
}

[fabian-hiller]

Thank you for creating this issue. Should schema be a JSON schema or a Valibot schema?

[andrewmd5]

Thank you for creating this issue. Should schema be a JSON schema or a Valibot schema?

Both, preferably. Currently I have to do this to silence incompatibility issues:

schema: union([
    pipe(
      custom<BaseSchema<unknown, unknown, BaseIssue<unknown>>>((s) => {
        if (
          s != undefined &&
          typeof s === 'object' &&
          'kind' in s &&
          s.kind === 'schema'
        ) {
          return true;
        }
        return false;
      }),
      transform(toJsonSchema)
    ),
    custom<JSONSchema7>((s) => {
      if (s != undefined && typeof s === 'object' && '$schema' in s) {
        return true;
      }
      return false;
    }),
  ]),

[fabian-hiller]

I would recommend to define a Valibot schema that matches the structure of a the Valibot BaseSchema or a JSON Schema.